Gyro

Gyro is a term used to refer to several related but distinct things, most commonly a Greek dish and a spinning mechanical device. The two share a root in the Greek word gyro, meaning circle or turn.

The gyro is a Greek dish consisting of meat cooked on a vertical rotisserie, shaved off and served in pita bread with toppings such as tomato, onion, and tzatziki sauce. In Greece the meat is typically pork, while outside the country the dish is often made with lamb, chicken, or beef. The gyro is similar to doner kebab and shawarma, but varies in seasoning and bread. The dish gained international popularity in the 20th century with Greek immigration.

A gyroscope is a device that uses the conservation of angular momentum to maintain or measure orientation. A rotor spins rapidly about its axis, and the resulting angular momentum resists changes in the axis direction; when a torque is applied, the wheel precesses rather than tilting in the direction of the torque. Gyroscopes have wide uses including navigation systems, stabilizers for ships and aircraft, and gimbal-mounted cameras, as well as microelectromechanical systems (MEMS) used in smartphones, drones, and gaming devices.

A gyrocompass is a type of gyroscope-based instrument that uses gravity and Earth's rotation to find true north, avoiding magnetic interference. Modern gyroscopes also appear as MEMS sensors used in portable electronics, vehicle stability systems, and inertial navigation.